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| author | Hans de Goede <hdegoede@redhat.com> | 2021-08-16 13:30:07 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-08-16 18:32:02 +0200 |
| commit | b25d5a1cd19896bb87b399d6e24896cf6f854d44 (patch) | |
| tree | b334601a18f581fea190dad06855bb7c4aecb6ad | |
| parent | 7c60610d476766e128cc4284bb6349732cbd6606 (diff) | |
| download | lwn-b25d5a1cd19896bb87b399d6e24896cf6f854d44.tar.gz lwn-b25d5a1cd19896bb87b399d6e24896cf6f854d44.zip | |
ACPI: platform-profile: call sysfs_notify() from platform_profile_store()
Drivers like thinkpad_acpi and ideapad_laptop call the
platform_profile_notify() helper when the profile is changed by hardware
(the embedded-controller/EC) in response to an EC handled hotkey.
This allows userspace to monitor for such changes by polling for POLLPRI
on the platform_profile sysfs file. But the profile can also be changed
underneath a userspace program monitoring it by anonther userspace program
storing a new value.
Add a sysfs_notify() call to platform_profile_store(), so that userspace
programs monitoring for changes also get notified in this case.
Also update the documentation to document that POLLPRI polling can be
used to watch for changes.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | Documentation/ABI/testing/sysfs-platform_profile | 7 | ||||
| -rw-r--r-- | drivers/acpi/platform_profile.c | 3 |
2 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-platform_profile b/Documentation/ABI/testing/sysfs-platform_profile index dae9c8941905..baf1d125f9f8 100644 --- a/Documentation/ABI/testing/sysfs-platform_profile +++ b/Documentation/ABI/testing/sysfs-platform_profile @@ -26,3 +26,10 @@ Contact: Hans de Goede <hdegoede@redhat.com> Description: Reading this file gives the current selected profile for this device. Writing this file with one of the strings from platform_profile_choices changes the profile to the new value. + + This file can be monitored for changes by polling for POLLPRI, + POLLPRI will be signalled on any changes, independent of those + changes coming from a userspace write; or coming from another + source such as e.g. a hotkey triggered profile change handled + either directly by the embedded-controller or fully handled + inside the kernel. diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c index dd2fbf38e414..d418462ab791 100644 --- a/drivers/acpi/platform_profile.c +++ b/drivers/acpi/platform_profile.c @@ -106,6 +106,9 @@ static ssize_t platform_profile_store(struct device *dev, } err = cur_profile->profile_set(cur_profile, i); + if (!err) + sysfs_notify(acpi_kobj, NULL, "platform_profile"); + mutex_unlock(&profile_lock); if (err) return err; |